Signaling system



J. C. FIELD.

SIGNALING SYSTEM.

APPLICATION FILED APR.13, I918.

Patented Feb. 8, 1921.

UNITED STATES PATENT OFFICE.

JOSEPH O. HELD, ORANGE, NEW JERSEY, ASSIGNOR 'IO WESTERN ELECTBIG COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION 0] NEW YORK.

SIGNALING- SYSTEM.

Specification of Letters Patent.

Patented Feb. s,' 1921.

Application filed April 13, 1918. Serial No. 228,417.

citizen of the United States, residing at Oran e, in the county of Essex, State of New ersey, have invented certain new and useful Improvements in Signaling Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to signaling systems and more particularly to selective signaling systems in which each of a plurality of stations connected with a pair of line wires is provided with a selectively operated signal control device.

An object of this invention is to provide in a system of this character improved means for communicatmg the correct time simultaneously to all stations connected with the line wires.

Another object of the invention is to provide a system of this character in which the time signals may be reeeived without interfering with a conversation being carried on over the line wires.

In accordance with this invention, after the si alcontrol devices at the various stations connected with the line wires have been conditioned for receiving time signals, the first energization of a time repeating relay connected in a time circuit causes the operation of apparatus to connect a source of current with the line wires for causing the operation of the signaling devices at the several way-stations, and upon the second energization of the time repeating relay, the apparatus operates in a different manner to connect current with the line wires for again causing the operation of thesignaling devices. When selectivelycalling any station connected with the line wires, the closure of a stationcontactvestablishes an operating circuit from the local signaling device, the association of which with the line wires is such that in operating, a return or answer back signal is transmitted to the central station. When the selectively operated signal control devices are conditioned for receiving time signals, the association of the local signaling devices, when the time signals are being received, is such as to efiectivel'y insulate the local signaling devices from the line wires, thereby preventing any disturbance on the line wires during the transmitting and receivingof time signals. 1 In this manper the reception of time signals will not mterfere with the carrying on of the conversatlon.

This invention will be more fully understood from the following description considered in connection with the accompanying drawings, wherein Figure 1 is a dia-- gram of circuits and apparatus illustrating the mvention; Fig. 2 shows an alternative form of control device for use at the central station; and Fig. 3 shows in detail how the elongated holding pin of a selector is secured to the step-b -ste element.

In Fig. 1 o the rawing, 5 and 6 designate a pair of line wires with which are associated a central or transmitting station A and a plurality of Way-stations,- two of which, B and C, are shown. At each of the way-stations B and C is a selectively operated signal controlling device, each of which comprises in general a polarized operating magnet 7, a step-by-step element 8 carrying a contact arm 9, and stationary contact elements 10 and 11. The step-by-step element 8 is 'mounted upon a shaft and is held in the position shown by means of a coiled spring 56, one end of which is secured to the shaft 55 and the other end of which is held in fixed position. In order that the contact-carrying element 8 may be advanced step by step against the action of the coiled spring 55, there is mounted upon the shaft 55 a ratchet wheel 53 adapted to be engaged bya stepping pawl 13 and a holding pawl 54. The stepping pawl 13 is mounted upon the outer end of a pivoted rocker arm 50 while the holding pawl 54 is pivotally mounted and controlled by the rocker arm 50. The centrally pivoted armature '12 carries an S shaped arm 49 upon. which are nlilounted pins 51 and 52, so positioned that t e roc er arm 50, whereby the stepping pawl 13 is caused to engage the ratchet wheel 53 upon each ener 'zation of the selector magnet 7 The ho ding pawl 54 is adapted to maintain the ratchet wheel and contactcarrying element 8 in advanced position during a reversal of current through the windings of the selector. magnet. Upon the cessation of'the last stepping impulse of the series which advance the element 8 into position where the contact arm 9 carried thereby engages the stationary contact 10, the pivimpinge upon opposite sides of the condenser 24, the windings of'vihrating bell 17, contact 10, contact/arm 9, step-by-s'tep element 8, pin and holding'sprmg 14, is

alternately closed and opened to cause the transmission of an answer back si centralstation A, where it is received inthe receiver 25. The element 8 is held in this contact-engaging position until further pulses are transmitted through .the winding of the selector magnet to advance the element 8 to a position where upon the cessation ofthe last of these impulses holding spring 14 will not engage the holding pin carried by the element 8. The coiled spring 56 thereupon returns the element 8 to normal posi-- tion.

The stepping mechanism of the selector is also adapted in response to a predetermined number of alternating current impulses through the selector magnet to advance the contact-carrying element 8 into a position where upon the cessation of the last impulse the spoon-ended holding spring 14 moves into engagement with the spoon-ended holding member 16 which (as shown in Fig. 3)

is secured to but insulated from the lower side of the contact-carrying element 8. In this predetermined advanced position of the contact-carrying element 8, the contact arm 9 is within one step of the contact 11, and the element 8 is held in this position against the action of the coiled spring 56. The subsequent energization of the selector magnet 7 in response to an impulse of either polarity through the windings thereof, while the contact arm 9 is being held within one step of the contact 11, causes the stepping mechanism to advance the contact-carrying member one step bringing contact arm 9 into engagement with contact 11. Upon the cessation of the energizing impulse, the centrally pivoted armature 12 returns to its normal position 'ermitting the spoon-shaped end of the ho ding spring 14 to move into engagement with the elongated tail piece of the holding member 16 and permitting the stepping and holding pawls 13 and 54 to move out of engagement with the ratchet wheel 53. The coiled spring 56 thereupon returns the con'tact-carryin element 8 into its prior predetermined a vanced position with C ntact am 9 withinone step of thealto the contact 11' and the spoon-shaped ends of the holding spring 14 and member 16 in engagement. To return the contact-carrying element to its normal position,v suificient impulses must first be transmitted through the windings of the selector magnet 7 to advance the element 8 such a distance that upon the cessation of the last impulse the spoonshaped end of the holding spring will not engage the elongated tail piece of the holding member. he coiled spring .56 then, after the movement of the stepping and holding pawls 13 and 54 out of engagement with the ratchet wheel 53, returns the contact-carrying element to its normal position. Since the holding member 16 is insulated from the step-by-step element 8, no circuit across'the line wires will be completed when the holding spring 14 engages the holding member 16, or when the contact arm 9 engages the stationary contact 11.

The selectively operated signaling device illustrated in the drawing which is of the type disclosed in my Patent No. 1,343,256, dated June 15, 19 20, is provided with one or more intermediate holding pins mounted 1 on the element 8 which are variously positioned in different selectors, whereby for a predetermined code or combination of impulses transmitted, the station contact, namely contact 10, of but one way-station connected with the line will be engaged by its associated contact arm 9. In fact, the

contact arm at but one of the stations will be advanced as far as its station contact 10. It will be understood that the same number of impulses are transmitted for selecting the various way-stations, the grouping of these impulses bein different for the different stations. To a vance the contact-carry. ing elements 8 of all stations into the position where they are held by the coiiperating holding spring and member 14 and 16 Connected to the line wires 5' and 6 at each of the way-stations, is an inductive bridge comprising the two impedance coils 20 and 21 and the windings of the selector magnets 77', included in serial relation with respect to each'other.

Located at the central station his a sending battery 30, the connection of which'with the line Wires 5 and 6 is controlled by a relay 31 and a pole chan ing relay 32 in energizing circuits control ed by a sending key comprising contact spring 33 and contacts 34 and 35. When the sending key is. et for operation, contact spring 33 engages and remains in engagement with contact 34 during all of the time that the key is in operation, thereby to maintain relay 31 energized. Contact spring 33 intermlttently engages contact 35 during the operation of the key, thereby intermittentl energizing the pole changing relay 32. 11 order to prevent the selecting impulses from the sending battery 30 from interfering with the proper operation of any telephone apparatus which may be connected with the line wires, there are provided retardation coils 36 and 37 in series with the line wires and condenser 38 and resistance 39 in bridge thereof which cooperate to smooth out the sending impulses in a manner well understood.

There is also located at the sending station A a time repeating relay 40 connected in a time circuit which controls a selector of precisely the same type as those shown atstations B and C. The windings of this selector are bridged by a condenser 29 of such capacity that the selector is rendered non-responsive to very rapid closure and opening of the contacts of the repeating relay 40. Therefore, after the way-station apparatus has been conditioned for receiving time signals, should trouble develop on the time circuit, causing the transmission of impulses in rapid succession over the time circuit, the non-response of the selector at station A therefore prevents the advancement of the way-station selectors. The adjustment of this selector, however, is such that when the stepping pawl 13 has advanced the step-by-step element 8 one step, the contact arm 9 is in engagement with the stationary contact 10 and upon the cessation of the impulse the magnet 7, the spoon-ended holding member 14 engages holding pin 15 to maintain the step-bystep element in contact engaging position against the action of the coiled spring 56. When the arms of a double-pole double-throw switch 41 are in their left-hand position, relav 31 is energized and the pole changing relay 32 is controlled by contact arm 9 of the selector at station A, and when the switch arms are in their right-hand position, relay 31 is controlled by contact spring 33' and contact 34, and the pole changlng rela 32 by contact spring 33- and contact 35. The general construction of the selector at the central or sending station A is similar to that of the selectors at the way-stations B and C. The selector at the sending station A is, however, not equipped with a spoon-ended holding member 16. The step-by-step element 8 of this selector however, is so positioned that the movable contact 9 is normally within one step of the stationary contact 10.

In Fig. 2 there is shown a form of controldevice which may be employed at the central station A instead of the selector shown in cm 47, thereby causing the end of the con- Fig. 1. This control device comprises an electromagnet 42, an armature 43 with which is connected a pawl 44 adapted to engage a ratchet wheel 45 mounted u n a shaft 46. A cam 47 is also fixed to the aft 46 for controlling contacts 48 and 49. Upon the energization of the magnet 42, the armature 43 is attracted to cause the pawl 44 to e age the ratchet wheel 45 and rotates the sha 46 and tact spring 48 to ride upon one of the elevations of thecam 47 and engage the contact 49. Contact spring 48 and contact 49 of Fig. 2 correspond to the contact arm 9 and the stationary contact 10 of the selector at station A. Condenser 29 in brid e of the winding of electromagnet 42 per ormsthe same function as condenser 29 of Fig. 1.

When the system is in condition for selectively calling any of the way-stations from the central station, the two arms of'the double-pole double-throw switch 41 are in their right-hand position. To call any station, the sending key may be actuated to close contacts 33 and 34, thereby energizing relay 31 to connect the sending battery 30 with the line wires, and the contacts 33 and 35 may then be engaged and disengaged throu h the intermediate contact 34 a number 0? times sufiicient to cause the transmission of the requisite number of positive and negative impulses for advancing the stepby-step element of the desired station to circuit closing position to operate the vibrating bell thereat. In such contact engaging" position at the cessation of the last selecting impulse, the spoon-ended holding spring 14 engages holding pin 15 to maintain the stepby-step element in contact engaging position against the action of the coiled spring 56. r

When the way-stations are to be conditioned for simultaneously receiving time si nals, the sending key is actuated to transm1tthe number of impulses required for 1 causing all selectors to advance their stepby-step elements 8 into a position where, upon the cessation of the,last stepping impulse, the spoon-ended holding spring 14 engages the spoon-ended holding member 16 to maintain the step-by-step elements 8 in position with the contact arm 9 within one step of thestationary contacts 11. The attendant at station A may now move the two arms of the double-pole double-throw switch from their right to left-hand position. Relay- 31 is thereupon energized to connect the sending battery with the line wires 5 and 6. When the repeating relay 40 is energized in response to an impulse of current over the time circuit, the local circuit including the magnet 7 of the selector at the central station A is closed, thereby causing the stepping pawl 13 to advance the step-by-step element 8 one step to cause'the contact arm 9 hit engagement of this contact 9 and the contact.

10 causes the energization of the pole changing relay 32 over a circuit from the lower terminal of battery 50 through contact arm 9, contact 10, lower arm of the double-pole double-throw switch 41, Winding of the pole changing relay 32 to the upper terminal of battery 50, Pole chan ing relay 32 m operating reverses the poiarity of the sending battery 30 connected with the line wires, thereby trensmitting an impulse of current through the magnets "Z of all selectors, Each Way-station selector magnet is thereupon energised to cause its stepping pawl 13 to advance the step-by-step element 8 one step, whereby the contact arm 9 engages stationary contact ll to close the circuit of v brating bell 1?. Upon the cessation of this impulse over the line Wires, due to the presence oi the condensers in series with the waystation magnets, the magnets "Z are deenergized whereupon the coiled springs 56 move the step-loyetep elements baclr into po sition with the spoon ended holding spring.

.i, the spoonended holding nieim Etch step by-step element in returning to this position, causes the disenits ccntect 9 and contact it, thereby opening the opereting" circuit of the hell i? controiied thereby. s/Vhile the are being received, the vibratin bells 1'2, 1'? are not bridged across T.. .ce Wires, and their operetion will cause no such disturbance on the line es there is en ensvver-bacir signal is being transmitted. For it more detailed description: of the operation of the selectors the wayetations when receiving time signeis, reference iney be had to my co=pending application, rial lie, lfidfiii tiled April 24;, 19M", Upon the cessation o the impulse ovcrthe time circuit repeating relay 4:9 releases its arms ture, whereupon the magnet 7 oi? the selector at station A is deenergized. The spoonended holding spring it thereupon engages the holding pin 15 to rna'intein the step i step element Sin position with the contact arm 9 in engagement with the contact 10. lit will be understood therefore that the pole changing relay 32 is inainteined energized upon the cessation of the impulse over the time circuit,

' The repeating relay i0 is again energized in response to the next impulse over the time circuit, thereby again closing the energizing circuit for the magnet 7. The step-byste element 8 at the central station A is a v'anced one step to cause the contact'arrn 9 to disengage the contact 10, thereby opening the energized circuit of the pole changin relay 32. Upon the denergization of this Eels changing relay 32, the polarity of the attery 30 connected with the line. Wires reversed, thereby transmitting another im teeters pulse over the line wires to cause the selectors at all way-stations to advance their step-by-step elements one step, whereby the contact arms 9 tom orarily engage the contacts 11 as before. pon the cessation of the impulse over the time circuit, repeating relay 40 is denergizcd and magnets 7 of the selector at station A are also deiinergized, whereupon the step-by step element 8 is re turned to normal position,

From this description it will be understood that the selector at the central station is advanced to the circuit closing position in response to the first impulse over the time circuit to cause the energization of the pole changing relay, and that in response to the second impulse over the time circuit, the selector is advanced to open the energizing circuit oi the pole changing relay, thereby peromitting its deenergization, it vviil be e en, therefore, that but one impulse of current is transmitted from the sending battery over the line Wires in response to each impulse over the time circuit.

iii the control device of 2 be eubstituted for the selector at station A, the first energization of the magnet-d2 a result of the first impulse over the time circuit causes the closure of contacts 48 and 4:9 and the ergizetion oi the pole changing relay 39;, 1 While the second impulse over time cuit causes the disengagement o1" and 4:9 and the deenei no pets changing relay 392, l devices, therefore, perform the same in ctions,

What is claimed is:

i, in a signaling system, in combination, a line circuit having a sending plureh ity of way-stations connected therewith, a selective signaling device connected with the i line circuit at each Way-station, means at the sendingstatiori for preparing the signaling devices to receive a signal simnitaueously ail Way-stations, a time circuit, a relay the time circuit, and means the sending; station responsive to an'energization oi the relay to connect with the line Wires current of one p'o larity for operating all signaling; devices, and in response to a succeeding energization oi the relay to connect with the line circuit current of opposite polarity tor again operating all signaling devices.

2. in a signaling system, in combination, line circuit having asending and a plurality of Way-stations connected therewith, a selective signaling device connected with the line circuit at each Way-station, means at the sending station for preparing the sig'i'nilinn devices to receive a signal simultaneously at all Way-stations, a time circuit, a relay in the time circuit, and means at the sending eta-- tion responsive to an nergization 'oi-the relay to connect a source of'current" with the line circuit for operating all signaling devices and difierently responsive to a succeeding energization of therelay to connect the.

source of current with the line wires for a selective signaling device connected with;

the line circuit at each way-station, means at the sending station for preparing the signalloj'ing devices to receive a signal simultaneline circuit having ously at all way-stations,"a time circuit, an

electromagnetic switching device energized in response to each impulse over the time circuit, a source of current, and a pole changing relay-attire sending station energized upon the first response of the electro-' magnetic switching device to transmit over the line wires an impulse of one polarity from said source for causing the operation of the signaling devices and deenergized upon the second response of the electromagnetic-switching device to transmit over the line wires an impulse of opposite polarity from said source for again causing the operation of the signaling devices. c

4:. In a signaling system,incombination, a

a sending and a plurality of way-stations connected therewith, an electromagnetic. step-hy-step selector at each way station responsive to current impulses, a signaling device controlled by each selector, means at the sending station for causing the advancement of allselectors to a predetermined position, a time circuit, a

source or current, and means at the sending tron actuated lnresponse to an impulse over the time circuit to transmit over the line wires an impulse of one polarity from said source and actuated in response to the succeeding impulse over the time circuit to transmit over the line wires an impulse of opposite polarity from said source, the selectors at all way-stations advancing one step to momentarily operate the signaling devices in response to each impulse over the line circuit.

'5, In a signaling system, in combination, line wires having a sending and a plurality of way-stations connected therewith, an electromagnetic step-by-step selector at each way-station responsive to current impulses,

means at the sending station for advancing any selector into a first predetermined position and also for simultaneously advancing all selectors into a second predetermined position, a signaling device at each way-statlon operating when lts selector is advanced into its first predetermined position and intermittently connected with the line wires during its operation, means rendered effective by the operation of the signaling device to transmit a signal tothe sending station, means at the sending station-for causing a one step advancement of the selectors from the second predetermined position to operate the signaling devices, and means to prevent the connection of the signalingdevices with the line wires when operating after the one ste advancement.

n witness whereof I hereunto subscribe my name this 9th da of A ril A. D. 1918 J osEP e. FIELD. 

